If $$0^\circ < \theta < 90^\circ$$, then $$\frac{(1 - \sin \theta)(\sec \theta + \tan \theta)\tan \theta}{(\tan \theta + \sec \theta + 1)(\cot \theta - \cosec \theta + 1)} = ?$$

A

$$\sin \theta$$

B

$$\frac{\sin \theta}{2}$$

C

$$\cos \theta$$

D

$$\frac{\cos \theta}{2}$$